New research has linked the use of Prozac and other similar antidepressants during pregnancy to yet another complication in newborns: an uncommon but life-threatening lung problem.
Infants whose mothers took the antidepressants in the second half of pregnancy had six times the expected risk of developing the lung disorder, the researchers reported in Thursday’s New England Journal of Medicine.
The antidepressants implicated are called selective serotonin reuptake inhibitors, or SSRIs, a class of drugs that includes Prozac, Paxil and Zoloft.
“This is the latest in a series of troubling reports of possible adverse effects of SSRIs on the fetus,” Dr. James L. Mills of the National Institute of Child Health and Human Development wrote in an accompanying editorial.
Other research has linked use of the antidepressants late in pregnancy to jitteriness, irritability, low blood sugar and difficulty breathing in newborns. The Food and Drug Administration warned last year that Paxil may be associated with heart defects when taken during the first three months of pregnancy.
For ethical reasons, medications cannot be tested on pregnant women, and the possible effects of a drug on a fetus can only be observed after the medicine is on the market and in use.
One of the researchers, Christina Chambers of the University of California at San Diego, said of the findings, “If it’s a true risk, it’s very low.” According to the researchers’ calculations, 99 percent of women who took the antidepressants late in pregnancy would deliver a child without the problem.
Dr. Sandra Kweder, deputy director of the Food and Drug Administration’s Office of New Drugs, called the results worrisome and said the agency would be issuing a public health advisory in a few days.
“I would emphasize that this isn’t a cause for panic among women who are taking these medications,” Kweder said.
Women should not stop taking the antidepressants on their own and should check with their doctors if they have concerns, Kweder said. “For many women, the small risk suggested by this study may be outweighed by their own personal need for treatment of a mental health condition,” she said.
In the study, researchers looked at a problem called persistent pulmonary hypertension. The disorder develops after birth when the infant’s lungs do not quickly adapt and there is not enough oxygen reaching the blood. It occurs in one or two infants per 1,000 births.
The researchers interviewed the mothers of 377 infants who had the problem and asked them if they had taken any medication for depression while pregnant. The women were compared with the mothers of 836 healthy babies born about the same time.
Fourteen mothers whose infants had the complication reported taking SSRIs during the second half of their pregnancy, compared with six mothers in the comparison group. The researchers calculated the antidepressants increased the risk of the disorder six-fold.
They found no increased risk of the lung problem from SSRI use during the first half of pregnancy or from the use of other antidepressants during pregnancy.
Chambers and some of the other researchers have received research support from drug makers.